Traditionally, sucrose has been used in large quantity as a sweetener. Recently, however, sucrose has been being less preferred because of its strong sweetness. Further, sucrose has the defect in the major cause of dental caries.
In recent years, uses of several saccharides have been proposed to solve the defect of sucrose. Particularly, maltose, which is produced from starch, has characteristics such as a relatively low sweetness, less fear of causing dental caries, and good taste in comparison with sucrose. At present, powdery products comprising HCBM, “SUNMALT®” and “SUNMALT S®” are commercialized by Hayashibara Shoji, Inc., Okayama, Japan, as food-grade products, and are expected to be increased in their consumptions.
Powdery products comprising HCBM are usually produced from aqueous solutions comprising maltose as a material by molasses separation, block pulverization, or spray method.
In these methods, molasses separation is a production method for a powdery product comprising the steps of concentrating an aqueous solution comprising maltose as a material, cooling gradually the solution while stirring in the presence of a seed crystal of HCBM to produce a massecuite containing HCBM, separating the crystals formed in molasses by centrifugation, and collecting and drying the crystals. Although a crystalline maltose powder with extremely high-purity is obtainable, this method has the defect in a relatively low yield of HCBM powder because of the production of molasses.
In contrast, block pulverization method is a process for producing a maltose powder, which usually comprises the steps of concentrating an aqueous solution comprising maltose as a material to produce massecuite, solidifying the whole contents, aging, pulverizing, drying, and collecting the resulting powder. Spray method is a process for producing a maltose powder, which usually comprises the steps of concentrating an aqueous solution comprising maltose as a material to produce massecuite, spray-drying the massecuite, aging, and collecting the resulting powder. Although those methods are not able to increase the purity of maltose, they can powderize the whole contents without forming molasses and are advantageous for industrial production.
Particularly, block pulverization method is a process for producing a stable powdery product comprising HCBM, which usually comprises the steps of concentrating an aqueous solution comprising maltose, partially crystallizing HCBM by adding HCBM as a seed crystal to produce massecuite, solidifying the whole contents into a block form, aging, pulverizing, drying, and screening the powder. The product industrially produced by the block pulverization method has been commercialized by Hayashibara Shoji Inc., Okayama, Japan, as “SUNMALT®”. By the block pulverization method, all of the maltose can be powderized and is advantageous for industrial production. However, the block pulverization method has the defect of requiring complicated processes of pulverization, drying, and screening as well as requiring a long production period of 5 to 15 days for solidifying massecuites into a block form and for aging.
On the other hand, as disclosed in Japanese Patent Kokai Nos. 3,937/79 and 27,325/79, there has been known that a process for producing a powdery product comprising HCBM by a spray method, which comprises the steps of concentrating an aqueous solution comprising maltose, partially crystallizing HCBM by adding HCBM as a seed crystal to produce a massecuite, powderizing by spray-drying and aging. The spray method is most advantageous for industrial production because it does not require a long term for solidifying massecuites and for aging. However, the spray method requires a three to four day production period and has difficulty in producing powdery products smoothly and continuously.
Thereafter, to improve the above problem, a process for producing a powdery product comprising HCBM, which can be produced in a relatively short time by spray method, has been established by using an aqueous solution containing an extremely high purity maltose with a purity of about 95 w/w % (throughout the specification, “w/w %” is abbreviated as “%” hereinafter, unless specified otherwise) or more, on a dry solid base (d.s.b.); decreasing the contents of saccharides except for maltose, particularly, decreasing the contents of glucose, maltotriose, and saccharides, with a glucose polymerization degree of four or higher, as low as possible. The product has been commercialized by Hayashibara Shoji Inc., Okayama, Japan, as a trade mark of “SUNMALT S®”. However, it is revealed that the powdery product comprising HCBM, which is obtainable by spray method, has, unexpectedly, an unsatisfactory solubility in aqueous solvents, that should be improved.